ajv "schema is invalid" error in CI

By Daniel Zoghalchali·Latchkey

ajv rejected the schema itself (not the data). In strict mode it fails on unknown keywords, unknown formats, or a $schema draft it does not support, reporting "schema is invalid".

What this error means

ajv-cli aborts before validating data with "schema is invalid:" followed by details like "unknown format \"uri\" ignored" turned into an error, or "strict mode: unknown keyword".

Error: schema is invalid: data/properties/url/format must be equal to one of the
allowed values; strict mode: unknown format "uri"

Common causes

A format ajv does not know in strict mode

Formats like uri, email, and date-time live in ajv-formats; without it, strict mode treats the unknown format as an invalid schema.

A draft mismatch or unknown keyword

The schema's $schema targets a draft ajv is not set up for, or uses a keyword ajv does not recognize in strict mode.

How to fix it

Add ajv-formats for standard formats

Install and register ajv-formats (or pass -c ajv-formats to ajv-cli) so formats like uri are recognized.

npm i -D ajv-cli ajv-formats
ajv validate -c ajv-formats -s schema.json -d config.json

Select the right draft or relax strict mode

Pass the matching spec, or disable strict mode only if you cannot change the schema.

ajv validate --spec=draft2020 -s schema.json -d config.json
# or, as a last resort
ajv validate --strict=false -s schema.json -d config.json

How to prevent it

• Register ajv-formats whenever schemas use standard formats.
• Match ajv's --spec to the schema's $schema draft.
• Prefer fixing the schema over disabling strict mode.

Frequently asked questions

Related guides

References

• GitHub Actions documentation